1. Field of the Invention
The present invention relates to control lever assemblies for operating a control system of a vehicle. More specifically, the present invention relates to an improved control lever, especially suited for use with a front brake or manual clutch system of an off-road motorcycle.
2. Description of the Related Art
Control levers are commonly mounted near a handgrip portion of a motorcycle""s handlebar to permit a rider to operate a control system of the motorcycle, such as a front brake system or manual clutch system. Typically, the front brake system is hydraulically operated and, more recently, hydraulic manual clutch systems have also been utilized.
When used to operate a hydraulic control system, the control lever is arranged to rotate about a pivot axis and engage a piston of the control system to move the piston along an axis of motion and thereby operate the control system. Thus, articulating movement of the control lever results in linear movement of the piston.
For racing motorcycles in particular, it is highly desirable for the control lever to provide an accurate indication of the amount of force applied to the control system, so that the rider is able to effectively control the operation of the motorcycle. This is referred to as the xe2x80x9cfeelxe2x80x9d of the lever. A lever with good xe2x80x9cfeelxe2x80x9d enhances the rider""s control of the motorcycle and promotes optimum performance. Prior control lever designs often possess an undesirable amount of operating friction either at the interface of the lever and the piston, or within the lever itself, during operation which results in a poor xe2x80x9cfeelxe2x80x9d of the lever.
An aspect of the present invention involves the realization that prior control lever designs impart a force on the piston of the hydraulic control system that is not aligned with the piston""s axis of movement throughout the movement of the lever. This results in an undesirable transverse loading condition of the piston, which may cause premature wear of a piston sealing arrangement, or of the piston itself. The transverse loading may occur as a result of the undesirable amount of operational friction inherent in prior control lever designs, as described above. Accordingly, a preferred control lever reduces the operational friction to provide a good lever xe2x80x9cfeelxe2x80x9d and, preferably, substantially prevents transverse loading of the hydraulic piston of control system.
A preferred embodiment is a control lever for actuating a control system of a vehicle, the control system including a first portion mounted proximate a hand grip portion of the vehicle and defining a fluid cylinder. The control system also includes a piston movable along a longitudinal first axis of the fluid cylinder. The control lever assembly includes a lever body having a finger grip portion. The lever body defines a second axis substantially perpendicular to the first axis and is rotatable about the second axis to move the piston from a relaxed position to an actuated position. The lever body defines a third axis substantially parallel to the second axis. The lever also includes an engagement portion contacting the piston and rotating about the third axis when the lever body is rotated about the second axis. A force applied by the engagement portion to the piston moves the piston from the relaxed position to the actuated position. Wherein the first axis is fixed with respect to the second axis and the force is substantially aligned with the first axis when the piston is in both of the relaxed and actuated positions.
A preferred embodiment is a control lever for actuating a control system of a vehicle, the control system including a first portion mounted proximate a hand grip portion of the vehicle and defining a fluid cylinder. The control system further comprises a piston movable along a longitudinal first axis of the fluid cylinder. The control lever assembly includes a lever body having a finger grip portion and defining a second axis substantially perpendicular to the first axis. The lever body is rotatable about the second axis to move the piston from a relaxed position to an actuated position. The lever body also defines a third axis substantially parallel to the second axis. The lever further includes an engagement portion defining a circular peripheral edge surface about the third axis, which contacts the piston. The engagement portion rotates about the third axis when the lever body is rotated about the second axis. A force applied by the engagement portion to the piston moves the piston from the relaxed position to the actuated position and the first axis is fixed with respect to the second axis.
A preferred embodiment is a control lever for actuating a control system of a vehicle, the control system including a first portion mounted proximate a hand grip portion of the vehicle and defining a first fluid cylinder. A piston is movable along a longitudinal first axis of the first fluid cylinder. The control lever assembly includes a lever body having a finger grip portion, the lever body defining a second axis substantially perpendicular to the first axis. The lever body being rotatable about the second axis to move the piston from a first position to a second position. A shaft is fixed to the lever body and defines a third axis substantially parallel to the second axis. An engagement portion is held by the shaft and defines a contact surface for contacting the piston. The contact surface is configured to rotate about the third axis when the lever body is rotated about the second axis to move the piston from the first position to the second position.
A preferred embodiment is a control lever for actuating a control system of a vehicle, the control system including a first portion mounted proximate a hand grip portion of the vehicle and defining a first fluid cylinder and a piston movable along a longitudinal first axis of the first fluid cylinder. The control lever assembly includes a lever body having a finger grip portion and defining a second axis substantially perpendicular to the first axis. The lever body being rotatable about the second axis to move the piston from a first position to a second position and defining a third axis substantially parallel to the second axis. An engagement portion including an arm portion defines a contact surface for contacting the piston. A bearing assembly is operably positioned between the lever body and the engagement portion to permit the engagement portion to rotate about the third axis when the lever body is rotated about the second axis to move the piston from the first position to the second position.